Delete all users from a SharePoint group with Powershell

Add-PSSnapin Microsoft.SharePoint.Powershell

###########################
# "Enter the site URL here"
$SITEURL = "http://somesite.com"

# "Name of Site group from which users have to be removed"
$SITEGROUP = "Members"

###########################

$site = new-object Microsoft.SharePoint.SPSite ( $SITEURL )
$web = $site.OpenWeb()
"Web is : " + $web.Title

$oSiteGroup = $web.SiteGroups[$SITEGROUP];

"Site Group is :" + $oSiteGroup.Name
$oUsers = $oSiteGroup.Users

foreach ($oUser in $oUsers)
{
    "Removing user : " + $oUser.Name
    $oSiteGroup.RemoveUser($oUser)
}